Automatic damper



(No Model.)

S. P. SMITH.

AUTOMATIC DAMPER.

Fi Patented Aug. 4, 1885.

INVENTDR:

WITNESSES UNITED Srnrns ATENT Orricij.

SOLOMON 1 SMITH, OF XVATERFORD, NEXV YORK.

AUTOMATEC DAMPER.

SPEGIFICATION forming part of Letters Patent No. 323,539, dated August4,1885

Application filed April 16, 1884. (No model) To all whom it mayconcern.-

Be it known that I, SOLOMON 1?. SMITH, a citizen of the United States,residing at \Vaterford, in the county of Saratoga and State of New York,have invented new and useful improvements in Automatic Dampers, of whichthe following is a specification.

My invention relates to improvements in balanced automatic dampers forthe open end of the cold-air duct of an air-heating furnace forregulating the quantity of the air supplied to the heating-chamber ofsuch furnace, and for preventing the blowing of gusts into saidheating-chamber. In such damper it is nec essary to provide foradjustment to prevent a greater volume of air from blowing into theheating-chamber than the capacity of the latter to properly heat beforeits passage there from to the rooms to bewarmed. For this purpose Iprovide an adjustable balance-arm whereby to maintain the free end of adamper hung atand in contact with the roof of the air-conduit at such apoint between the roof and the floor of the duct as will lessen the areaof the entrance and give the required supply, and thus avoid filling theheatingchamber with air beyond its capacity to heat. A littleexperience, with the aid of a scale on the duct-wall and a glass door onthe opposite duct-wall, will afford facility for determining theposition at which the damper should be halancedthat is, the degree ofits inclination from the roof of the duct-so that, however the blastsmay vary in force and constancy, the quantity of air passing through theconduit will be regulated, so as to giveacomparatively uniform supply tothe heating chamber. XVhen there is no wind blowing, the damper willvibrate with a tremulous motion imparted by the current of air inducedby the heat of the furnace. During high winds, however, the damper wouldbe vibrated with such violence as to cause it and its balancingarm tobeat against the roof with such force as to be annoying to the occupantsof the house. To avoid such annoyance, I provide roof-cushi0ns to deadenthe sudden blows of the damper and of its balancing weight. In applyingthe damper to a furnace having a cold-air inlet 18x18, giving threehundred and twenty-four inches area, I balanced the damper atthreehundred and twenty-four square inches when the inlet-opening was closed,and found it to suit the heating capacity of the furnace and the draftof the duct. A change in the area of the inlet, a different draft in theduct, and a furnace having a different heating capacity would haverequireda different adj ust-ment of the damper, and as these conditionsare more or less changedin every furnace the provision for adjusting thedamper to suit them is important. A weighted damper cannot operateeffectively without provision for ready adjustment to the extent thatwill give perfect balance in whatever position it may be set to suit theconditions stated.

In the drawings accompanying and forming part of the specification,Figure 1 represents the section of a part of a furnace or buildinghaving an air-flue constructed therein with the automatic mechanismattached. Fig. 2is a longitudinal elevation of a flue with the automaticdamper mechanism attached, and the same set in a certain position. Fig.3 is a side view of the damper in different positions, as shown indotted lines; and Fig. at is a plan view of the damper with thecounterbalancingweight.

In the accompanying drawings, A, Fig. 1, is a part of a furnace orbuilding having constructed within it the air-flue B, as shown.

C is the damper or door provided at each corner of its upper edge withthe journals cc, which turn freely in the bearings b b, firmly attachedto the roof of the fine. The upper edge of the door is set into orconnected with the transverse rod or bar c, on the ends of which thejournals 0 c are fixed. The rod 0' lies and turns in contact with theroof of the line, so that but little air can escape over the top of thedoor. The door 0 is considerably longer than the vertical transversesection of the air-flue, so that when it entirely closes the said fineit makes an acute angle with the floor of the same.

D is the threaded lever attached to the up per edge of the door. Thelever D has one end fixed to the middle part of the rod 0 and extendsinwardly from the same, making such an angle with the plane of the doorthat when the latter is closed the countcrbalaiming-weight (1 will comein contact with the roof of the flue. The weight (Z is longitudinallyadj ustable on the rod D, so as to increase or diminish its leverage, asshown.

E is a scale of equal parts attached within and on one side of the flueto show how much of the area of the transverse section of the flue thedoor leaves nnclosed when in any given position. Thus when the loweredge of door is at 12, onetwelfth of a square foot or twelve squareinches (if the dimensions are in feet and inches) will be open for thepassage of air, and for each following division of the scale twelvesquare inches of open orifice will be added, at 144 there being thenjust one square foot of such orifice.

F is a door, provided with a glass-covered opening, hinged to the sideof the flue at a point corresponding to the position of the antomaticclosing mechanism just described. By means of this door the operation ofthe damper may be watched, and any desired adjustment of thecounter-balance may be made.

G G are bull-lug devices attached to the roof of the flue in suchpositions as to buff the damper and the lever D, so as to prevent jar ornoise when the damper is acting.

If it is desired to lessen the whole quantity of inflowing air, theblock may be so adjusted on the lever as to hold the door at anyrequired point on the scalewith the normal draft, for instance. Shouldbut one-half of the quantity which is the natural capacity of the due bedesired, the block would be adjusted so that the lower edge of the doorwould set at 72 on the scale. On the other hand, should a blast beestablished through the line and it be desired to pass more air than thequantity which represents the natural capacity of the same, the block (Imay be adjusted to hold the damper against the roof of the flue with agiven force, which will have to be overcome before the blast can closethe damper.

I do not claim the damper hung in an inclined position to the roof ofthe cold-air eonduit, nor the damper so hung provided with a weightedarm whereby to maintain the damper in an open position against the roof,but improvements whereby such a damper is adapted for more satisfactoryuse under the varying conditions of supplying air to the heating-chamberof a hot-air furnace.

I claim- 1. The automatic damper herein described,

consisting of the open cold-air conduit B, having upon one of itsvertical walls an indicating-scale, the opposite wall having a hingedglass door, F, and between them a balanced damper provided with anadjustable weight, as and for the purpose specified.

2. The open cold-air conduit 13, having the roof-cushions G G, and thedamper 0, having the screw-threaded arin D, and the adjustable weight,the said cushions being arranged to receive the blows of the damper andweight, as and-for the purpose specified.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

SOLOMON P. SMITH. Vitnesses:

CHARLES BATCHELDER, CHARLES H. COLE.

